Photographic process



Patented May 2, 1933 UNITED STATES PATENT OFFICE MAXIMILIAN PAUL SCHMIDT, WTLHELM KRIEGER AND WALTHER SPIETSGHKA, Oll' WIESIBADE'N-IBIEBRICH, GERMANY, ASSIGNOR-i '10 KALLE & CO. AKTIENGESELL SCHAFT, OF WIESBADEN-BIEBRICH, GERMANY PHOTOGRAPHIC PROCESS No Drawing.- Application filed May 18, 1931, Serial No. 538,392, and in Germany May 28, 1930.

may, however, also contain an azo component besides the diazo compound. In this latter case, after exposure to light it is developed by means of an alkali, the dry developing process by means of gaseous alkalies being generally preferred. -Besides other additions generally employed in diazo-type processes, such as acids, as for instance, oxalic acid, tartaric acid, citric acid, stabilizers, as for instance, iiaphthalene-trisulfonic acid,

'thiocarbamide, etc. the light-sensitive layer of the film may also contain salts, as, for instance, nickel sulfate, copper sulfate, titanium-potassium oxalate which, in combination with the dyestuffs obtained by the development, yield particularly beautiful shades owing to the fact that a color lake is formed or that the dyestuff is formed in such a manner that its small particles are of a particularly favorable size. In these cases the development of the film which has been exposed to light in general does not immediately produce thefinal shade of the pictures. The said final shade, which is due to the formation of a color lake is usually only at-- tained after the expiration of a somewhat long time subsequent to the development.

It will be obvious that for technical purposes this long time which is required for obtaining the final shade ofthe picture constitutes somewhat of a disadvantage, inasmuch as it diminished the possibility of exposing to light and developing a large quantity of films in a short time.

We have found a process which permits of obtaining the. final shade of the pictures in a short time after the development, whereby it is rendered possible to expose, to develop and to finish alargeiquantity of films .in a short time. Thels'aid iprocess consists in after-treating the developed. films under drastically operative conditions, for instance, by treating them, after the development is complete, with steam at a high temperature, for instance, from 70 C. up to 150 C. The process vis preferably carried out by means of saturated steam, that is to say at a high temperature near the boiling point of water. When workingat an elevated'or reduced pressure, for instance, at a vacuum of 50 mm. mercury pressure orat superatmospheric pressures from I to 10 atmospheres, the

temperatures used can be correspondingly varied. The steam may be mixed with gases and vapors of other compounds, such as .acetic acid vapor or the like, whereby the process can be further accelerated.

The rapidity of this after-treatment can thus be adapted to the speed ofthe develop ment. The process, therefore, presents the possibility, when using a suitable apparatus,

of carrying out the steaming process directly following the developing process, so that a completely continuous production of the films is possible.-

For carrying out the new process a steaming apparatus, consisting of a double jacket pipe which is capable of being heated and in which the film is treated with steam at a high temperature according tothe countercurrent principle, has, for example, been found to be suitable. The steam flowing counter to the film has then to fulfill the task of freeing the film from the excess of ammonia and simultaneously producing the desired final shade in as short a time as possible. The said steaming apparatus can advantageously be combined with a developin apparatus wherein the film is developed y means of ammonia, if required at a. high temperature and with the aid of moisture.

Th following examples serve to illustrate i canal on the bottomof which is ammonia water and subsequently treated in a double jacket pipe with steam of about 100 C. By the latter treatment the final red shade is obtained.

2. A film from regenerated cellulose is rendered light-sensitive by soaking with the diazo compound of 1-bcnz iylamino-2.5-diethoxyl-aniline. After exposure it is developed by means of a dilute alcoholic-ammoniacal solution of 4 parts of resorcine and 1 part of phoroglucine and subsequently treated with steam as above indicated. A brown shade is obtained.

3. A film from regenerated cellulose is sensitized as described in Example 1; after exposure, this film is developed with ammonia in the presence of steam in a gas-tight canal under a superatmospheric pressure of 2 atmospheres. The developed film is then deaerated in a separate canal. under a vacuum of 30 mm. Hg. pressure. From this canal the film is brought into a double jacket pipe and is subjected therein to the action of saturated steam at about 135 C. and a superatmospheric pressure of 3 atmospheres. In this case the final red shade of the picture is reached in a shorter time than according to Example 1.

In the foregoing examples the steam used for finishing the shades of the pictures may contain an addition of another vapor, for instance, of acetic acid vapor. Furthermore the light-sensitive films may contain an addition of an acid, for instance, tartaric acid or/and of a stabilizer as, for instance, thiocarbamide. The processes of developing and finishing are the same as those described in Examples 1 to 3.

We claim:

1. In the process for continuously producing pictures on films by impregnating the films with light-sensitive diazo-components in mixture with azo-components and. a salt capable of forming a lake with the azo-dyestufl" obtained from the said components, exposing them to light and developing the picture in the usual manner, the step which comprises subjecting the films after the development of the picture to the action of steam at a high temperature.

2. In the process for. continuously producing pictures on films by impregnating the films with light-sensitive diazo-components in mixture with azo-components and a salt capable of forming-a lake with the dyestuii obtained from the said components, exposing them to light and developing the picture in the usual manner, the step which comprises subjecting the films a*-' ter the development of the picture tothe action of steam at a high temperature and an elevated pressure.

3. In the'process for continuously producing pictures on films by impregnating the films with light-sensitive diazo-components in mixture with azo-components and afsalt capable of forming a lake with the azo dyestuft' obtained from the said components, exposing them to light and developing the picture in the usual manner, the step which comprises subjecting the films after the development of the picture to the action of saturated steam at about 100 C.

4. In the process for continuously producing pictures on films by impregnating the films with light-sensitive diazo-components in mixture with azo-components and a salt capable of forming a lake with the azo dyestuif obtained from the said components, exposing them to light and developing the picture in the usual manner, the step which comprises subjecting the films after the development of the picture to the action of saturated steam at about 100 C. and an elevated pressure.

5. In the process for continuously producing pictures on films by impregnating the films with light-sensitive diazo-components in mixture with azo-components and a salt of a metal or the group consisting of nickel copper and titanium capable of forming a lake with the azo-dyestufi' obtained from the said components, exposing them to light and developing the picture in the usual manner, the step which comprises subjecting the films after the development of the picture to the action of steam at a high temperature.

6. In the process for continuously producing pictures on films by impregnating the films with light-sensitive diazo-components in mixture with azo-components and a salt of a metal of the group consisting of nickel, copper and titanium capable of forming a lake with the dyestutf obtained from the said components, exposing them to light and developing the picture in the usual manner, the step which comprises subjecting the films after the development of the picture to the action of steam at a high temperature and an elevated pressure.

7. In the process for continuously producing pictures on films by impregnating the films with light-sensitive diazo-components in mixture with azo-components and a salt of a metal of the group consisting of nickel, copper and titanium capable of forming a lake with the azo dyestufi obtained from the said components, exposing them to light and developing the picture in the usual manner, the step which comprises subjecting the films after the development of the picture to the action of saturated steam at about 100 C.

8. In the process for continuously producing pictures on films by impregnating the films with light-sensitive diazo-components in mixture with azo-components and a salt of a metal of the group consisting of nickel, copper and titanium capable of forming a lake with the azo dyestuff obtained from the' said components, exposing them to light and developing the picture in the usual manner, 

